Bromus catharticus Vahl

synonyms: Bromus unioloides, Bromus willdenowii


rescue grass, rescue brome


Info

Subfamily: Pooideae
Genus etymology: Bromus = "food" [Greek] the ancient name for oats (Avena)
Species etymology: catharticus = "purgative" [Latin] unclear
Photosynthetic type: C3 (cool season)
Nativity: naturalized - accidental
First recorded in Hawaiʻi: 1871

Map

 Distribution of Bromus catharticus in Hawaiʻi.
 Distribution of Bromus catharticus in Hawaiʻi.

Inflorescence

Bromus catharticus Inflorescence
Bromus catharticus Inflorescence
Bromus catharticus Inflorescence
Bromus catharticus Inflorescence
Bromus catharticus Inflorescence
Bromus catharticus Inflorescence
Bromus catharticus Inflorescence
Bromus catharticus Inflorescence
Bromus catharticus Inflorescence
Bromus catharticus Inflorescence

Plant

Bromus catharticus Plant
Bromus catharticus Plant
Bromus catharticus Plant
Bromus catharticus Plant
Bromus catharticus Plant

Habit

Bromus catharticus Habit
Bromus catharticus Habit

Spikelets

Bromus catharticus Spikelets
Bromus catharticus Spikelets
Bromus catharticus Spikelets
Bromus catharticus Spikelets
Bromus catharticus Spikelets
Bromus catharticus Spikelets
Bromus catharticus Spikelets
Bromus catharticus Spikelets
Bromus catharticus Spikelets
Bromus catharticus Spikelets
Bromus catharticus Spikelets
Bromus catharticus Spikelets
Bromus catharticus Spikelets

Description

Plants annual, biennial, or perennial; loosely cespitose or tufted. Culms 30-120 cm tall, 2-4 mm thick, erect or decumbent. Sheaths usually densely, often retrorsely, hairy, hairs sometimes confined to the throat; auricles absent; ligules 1-4 mm, glabrous or pilose, obtuse, lacerate to erose; blades 4-30 cm long, 3-10 mm wide, flat, glabrous or hairy on both surfaces. Panicles 9-28 cm, usually open, erect or nodding; lower branches shorter than 10 cm, 1-4 per node, spreading or ascending, with up to 5 spikelets variously distributed. Spikelets (17)20-40 mm, shorter than at least some pedicels and branches, elliptic to lanceolate, strongly laterally compressed, not crowded or overlapping, with 4-12 florets. Glumes smooth or scabrous, glabrous or pubescent; lower glumes 7-12 mm, 5-7(9)-veined; upper glumes 9-17 mm, 7-9(11)-veined, shorter than the lowest lemma; lemmas 11-20 mm, lanceolate, laterally compressed, strongly keeled, usually glabrous, sometimes pubescent distally, smooth or scabrous, 9-13-veined, veins often raised and riblike, margins sometimes conspicuous, hyaline, whitish or partly purplish, apices entire or toothed, teeth acute, shorter than 1 mm; awns absent or to 10 mm; anthers 0.5-1 mm in cleistogamous florets, 2-5 mm in chasmogamous florets. 2n = 42.
(Description source: Barkworth, M.E., Capels, K.M. & Long, S. (eds.) 1993. Flora of North America, north of Mexico. Volume 24. Magnoliophyta: Commelinidae (in part): Poaceae, Part 1. Oxford University Press, New York. 911 pp. http://floranorthamerica.org/Bromus_catharticus )

Stout annuals or short-lived perennials; culms erect to spreading, (2.5-)6-15 dm tall, glabrous. Sheaths 8-12 cm long, hirsute to pilose or rarely glabrous, often ciliate at throat; ligule 2.5-5 mm long, membranous, glabrous to pilose, apex erose; blades flat, 3-6 mm wide, retrorsely scabrous, sometimes sparsely pilose, auricles absent or minute. Inflorescence paniculate, (8-)12-45 cm long, the branches scabrous, 10-20 cm long, often drooping; spikelets 4- 7(-13)-flowered, strongly laterally compressed, (16-)20-45 mm long; glumes many-nerved, acuminate, strongly keeled, first glume (7-)8-11.5 mm long, second glume lanceolate to broadly lanceolate, 9- 13 mm long; lemmas 14-16 mm long, lanceolate, keeled, many-nerved, minutely scaberulous to glabrous, apex minutely bifid, awns, when present, up to 2.5 mm long; palea 8-10 mm long, acute, ciliolate. Caryopsis reddish brown, narrowly ovate, 12-14 mm long. [2m = 28, 42, 56.]
(Description source: O’Connor, P.J. 1990. Poaceae, pp. 1481–1604. In: Wagner W.L., Herbst D.R. & Sohmer S.H. (eds.)., Manual of the flowering plant of Hawaiʻi. Vol. 2. University of Hawaii Press & Bishop Museum Press, Honolulu )